MELBOURNE — Andy Murray was sucking in deep breaths, trying to recover from his exhausting win over Roger Federer. Pain was very much on his mind.

The US Open champion defeated Federer, 6-4, 6-7 (5-7), 6-3, 6-7 (2-7), 6-2, in a four-hour Australian Open semifinal Friday night. It was Murray’s first victory against the 17-time major winner at a Grand Slam event.